In typography, a serif/ˈsɛrɪf/ is a small line attached to the end of a stroke in a letter or symbol.[1] A typeface with serifs is called a serif typeface (or serifed typeface). A typeface without serifs is called sans serif or sans-serif, from the Frenchsans, meaning "without". Some typography sources refer to sans-serif typefaces as "Grotesque" (in German "grotesk") or "Gothic",[2] and serif typefaces as "Roman".

Serifs originated in the Latin alphabet with inscriptional lettering—words carved into stone in Roman antiquity. The explanation proposed by Father Edward Catich in his 1968 book The Origin of the Serif is now broadly but not universally accepted: the Roman letter outlines were first painted onto stone, and the stone carvers followed the brush marks which flared at stroke ends and corners, creating serifs. Another theory is that serifs were devised to neaten the ends of lines as they were chiseled into stone.[3][4][5]

The origin of the word serif is obscure, but apparently is almost as recent as the type style. In The British Standard of the Capital Letters contained in the Roman Alphabet, forming a complete code of systematic rules for a mathematical construction and accurate formation of the same (1813) by William Hollins, it defined surripses, usually pronounced "surriphs", as "projections which appear at the tops and bottoms of some letters, the O and Q excepted, at the beginning or end, and sometimes at each, of all." The standard also proposed that surripsis may be a Greek word derived from συν (together) and ριψις (projection).

In 1827, a Greek scholar, Julian Hibbert, printed with his own experimental uncial Greek types, remarking that the types of Giambattista Bodoni's Callimachus were "ornamented (or rather disfigured) by additions of what I believe type-founders call syrifs or cerefs." The oldest citations in the Oxford English Dictionary (OED) are 1830 for serif and 1841 for sans serif. The OED speculates that serif was a back-formation from sanserif. Webster's Third New International Dictionary traces serif to the Dutch noun schreef, meaning "line, stroke of the pen", related to the verb schrappen, "to delete, strike through". Schreef now also means "serif" in Dutch.

The OED‍ '​s earliest citation for "grotesque" in this sense is 1875, giving stone-letter as a synonym. It would seem to mean "out of the ordinary" in this usage, as in art grotesque usually means "elaborately decorated". Other synonyms include "Doric" and "Gothic," commonly used for Japanese Gothic typefaces.

Serifed fonts are widely used for body text because they are considered easier to read than sans-serif fonts in print.[6] However, scientific study on this topic has been inconclusive. Colin Wheildon, who conducted scientific studies in 1982–1990, found that sans serif fonts created various difficulties for readers that impaired comprehension.[7] According to Kathleen Tinkel, studies suggest that "most sans serif typefaces may be slightly less legible than most serif faces, but ... the difference can be offset by careful setting".[8] Other studies have found no significant difference in readability for serif or sans serif.[9][10]

Serifed fonts are overwhelmingly preferred for lengthy text printed in books, newspapers and magazines.[10] For such purposes sans-serif fonts are more acceptable in Europe than in North America, but still less common than serifed typefaces.[citation needed]

Sans-serif are considered to be legible on computer screens. According to Alex Poole,[9] "we should accept that most reasonably designed typefaces in mainstream use will be equally legible." A study suggested that serif fonts are more legible but are generally preferred less than sans serif fonts on screen.[11] Another study indicated that comprehension times for individual words are slightly faster when written in a sans serif font versus a serif font.[12]

Most web pages employ sans-serif type.[13]Hinting information, spatial anti-aliasing, and subpixel rendering technologies have partially mitigated the perception of serif fonts on screen. Due to the basic constraint of screen resolution—typically 100 pixels per inch or less—the serifs in some fonts can be difficult to discern on screen. Some serif fonts, such as Georgia, are specially designed for web readability—employing higher x-heights in the letters as well as sturdier serifs.

As serifs originated in inscription they are generally not used in handwriting. A common exception is the printedcapitalI, where the addition of serifs distinguishes the character from lowercaseL. The printed capital J and the numeral1 are also often handwritten with serifs.

Old style or humanist typefaces date back to 1465, shortly after Johannes Gutenberg's adoption of the movable typeprinting press. They are inspired by period handwriting such as humanist calligraphy and have remained popular for setting body text because of their excellent readability. Development of interest in early printing in the late nineteenth and early twentieth centuries saw a reversion to the designs of the earliest printers, many of whose names and designs are still used today.

The style is characterized by a lack of large differences between thick and thin lines (low line contrast) and generally but less often by a diagonal stress (the thinnest parts of letters are at an angle rather than at the top and bottom). An old style font normally has a left-inclining curve axis with weight stress at about 8 and 2 o'clock; serifs are almost always bracketed (they have curves which connect the serif to the stroke); head serifs are often angled.[14]

Old style faces are sub-divided into Venetian (or humanist) and Garalde (or Aldine). Venetian types, which are less popular, tend to feature an 'e' where the cross stroke is angled, not horizontal, and a slightly more irregular design.

Transitional or baroque serif typefaces first appeared in the mid-18th century. Fonts from this period include Baskerville (1757), while more recent fonts in the same style include Times New Roman (1932), Bookman, Century, Georgia and Plantin. They are in between modern and old style, thus the name "transitional." Differences between thick and thin lines are more pronounced than they are in old style, but they are still less dramatic than they are in modern serif fonts. Stress is more likely to be vertical. The ends of many strokes are marked not by blunt or angled serifs but by ball terminals.

Didone or Modern serif typefaces, which first emerged in the late 18th century, are characterized by extreme contrast between thick and thin lines. These typefaces have a vertical stress, long and fine serifs, with minimal brackets. Serifs tend to be very thin and vertical lines are very heavy. Most modern fonts are less readable than transitional or old style serif typefaces. Period examples include Bodoni, Didot, and Walbaum, while Computer Modern is a popular contemporary example.[15] While mostly used for headings and display text in the English-speaking world, in continental Europe they are commonly used for setting body text. They remain extremely popular in the printing of Greek, as the Didot family were among the first to establish a printing press in newly independent Greece.

Slab serif or Egyptian typefaces have very thick serifs, which tend to be as thick as the vertical lines themselves. Slab serif fonts vary considerably: some such as Rockwell have a geometric design with minimal variation in stroke width: they are sometimes described as sans-serif fonts with added serifs. Others such as those of the "Clarendon" model have a structure more like most other serif fonts, though with larger and more obvious serifs.[16] These designs may have bracketed serifs.

Because of the clear, bold nature of the large serifs, slab serif designs are often used for posters and in small print. Many monospace fonts, on which all characters occupy the same amount of horizontal space as in a typewriter, are slab serif designs. While not always purely slab-serif designs, many fonts intended for newspaper use have large slab-like serifs for clearer reading on poor-quality paper. Slab serif typefaces date to around 1800.

The earliest books were handwritten by monks in scriptoria, with many flourishes and embellishments to letters. The controversy continues over readability, without conclusive results.[17] Editors were formerly taught to use serif, as in older books. Magazines may use sans-serif as "cleaner", but possibly decreasing readability.[18] Modern e-book readers allow the viewer to adjust font family and size.

From left to right: a serif typeface with serifs in red, a serif typeface and a sans-serif typeface.

In the Chinese and Japanese writing systems, there are common type styles based on the regular script for Chinese characters akin to serif and sans serif fonts in the West. In Mainland China, the most popular category of serifed-like typefaces for body text is called Song (宋体, Songti); in Japan, the most popular serif style is called Minchō (明朝); and in Taiwan and Hong Kong, it is called Ming (明體, Mingti). The names of these lettering styles come from the Song and Ming dynasties, when block printing flourished in China. Because the wood grain on printing blocks ran horizontally, it was fairly easy to carve horizontal lines with the grain. However, carving vertical or slanted patterns was difficult because those patterns intersect with the grain and break easily. This resulted in a typeface that has thin horizontal strokes and thick vertical strokes[citation needed]. In accordance with Chinese calligraphy (kaiti style in particular), where each horizontal stroke is ended with a dipping motion of the brush, the ending of horizontal strokes are also thickened[citation needed]. These design forces resulted in the current Song typeface characterized by thick vertical strokes contrasted with thin horizontal strokes, triangular ornaments at the end of single horizontal strokes, and overall geometrical regularity.

In Japanese typography, the equivalent of serifs on kanji and kana characters are called uroko—"fish scales." In Chinese, the serifs are called either youjiaoti (有脚体, lit. "forms with legs") or youchenxianti (有衬线体, lit. "forms with ornamental lines").

The other common East Asian style of type is called black (黑体/體, Heiti) in Chinese and Gothic(ゴシック体,Goshikku-tai?) in Japanese. This group is characterized by lines of even thickness for each stroke, the equivalent of "sans serif." This style, first introduced on newspaper headlines, is commonly used on headings, websites, signs and billboards.